Low temperature traps myosin motors of mammalian muscle in a refractory state that prevents activation.

ABSTRACT: Myosin motors in the thick filament of resting striated (skeletal and cardiac) muscle are trapped in an OFF state, in which the motors are packed in helical tracks on the filament surface, inhibiting their interactions with actin and utilization of ATP. To investigate the structural changes induced in the thick filament of mammalian skeletal muscle by changes in temperature, we collected x-ray diffraction patterns from the fast skeletal muscle extensor digitorum longus of the mouse in the temperature range from near physiological (35°C) to 10°C, in which the maximal isometric force (T ₀) shows a threefold decrease. In resting muscle, x-ray reflections signaling the OFF state of the thick filament indicate that cooling produces a progressive disruption of the OFF state wit

SUBMITTER: Caremani M 

PROVIDER: S-EPMC6829559 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature